Nacelle inlet structures, engine assemblies and vehicles including the same, and related methods

ABSTRACT

Nacelle inlet structures, engine assemblies and vehicles including the same, and related methods. A nacelle inlet structure of an engine assembly includes an inlet outer barrel and an inlet inner barrel with a tubular portion and an inlet attachment flange. The tubular portion of the inlet inner barrel extends at least partially along a direction parallel to the engine axis, while the inlet attachment flange extends from the tubular portion. The inlet attachment flange is integrally formed with at least a portion of the tubular portion of the inlet inner barrel. The inlet attachment flange is configured to be operatively coupled to an engine case of the engine assembly to operatively couple the nacelle inlet structure to the engine case. In examples, a method of manufacturing an inlet inner barrel includes forming a composite laminate with a composite manufacturing process.

RELATED APPLICATION

The present application is a non-provisional of and claims priority toU.S. Provisional Patent Application No. 63/183,754, filed on May 4,2021, entitled “NACELLE INLET STRUCTURES, ENGINE ASSEMBLIES AND VEHICLESINCLUDING THE SAME, AND RELATED METHODS,” the complete disclosure ofwhich is incorporated by reference.

FIELD

The present disclosure relates to nacelle inlet structures, engineassemblies and vehicles including the same, and related methods.

BACKGROUND

In various examples of engine assemblies, such as aircraft turbofanengines, a nacelle inlet structure forms a duct for introducing an airflow into an engine. In some such examples, the nacelle inlet structureis operatively coupled to an engine case that supports and/or enclosescomponents of the engine, such as a fan of the engine. In particular, insome such examples, the nacelle inlet structure and the engine caseinclude respective annular flanges that are operatively coupled to oneanother via a plurality of mechanical fasteners. In some examples, theattachment flange of the nacelle inlet structure takes the form of ametallic ring that is operatively coupled to another component of thenacelle inlet structure, such as via mechanical and/or blind fasteners.However, such metallic rings may be undesirably massive, and thecorresponding fasteners may be expensive and/or time-intensive toinstall and/or maintain.

SUMMARY

Nacelle inlet structures, engine assemblies and vehicles including thesame, and related methods are disclosed herein. A nacelle inletstructure of an engine assembly includes an inlet outer barrel and aninlet inner barrel with a tubular portion and an inlet attachmentflange. Each of the inlet inner barrel and the inlet outer barrelextends circumferentially around an engine axis of the engine assemblyand extends at least partially along a direction parallel to the engineaxis. The tubular portion of the inlet inner barrel extends at leastpartially along a direction parallel to the engine axis, while the inletattachment flange extends from the tubular portion. The inlet attachmentflange is integrally formed with at least a portion of the tubularportion of the inlet inner barrel. The inlet attachment flange isconfigured to be operatively coupled to an engine case of the engineassembly to operatively couple the nacelle inlet structure to the enginecase.

In some examples, a method of manufacturing an inlet inner barrelincludes forming, with a composite manufacturing process, a compositelaminate that includes a back skin and an inlet attachment flange.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representation of an example of a vehicle in the form of anaircraft that includes engine assemblies with nacelle inlet structuresaccording to the present disclosure.

FIG. 2 is a schematic cross-sectional side elevation view representingan example of a nacelle inlet structure according to the presentdisclosure.

FIG. 3 is a schematic fragmentary cross-sectional side elevation viewrepresenting a portion of an example of a nacelle inlet structureaccording to the present disclosure.

FIG. 4 is a schematic fragmentary cross-sectional side elevation viewrepresenting portions of examples of nacelle inlet structures accordingto the present disclosure.

FIG. 5 is a flowchart representing examples of methods, according to thepresent disclosure, of manufacturing an inlet inner barrel of a nacelleinlet structure.

FIG. 6 is a schematic cross-sectional side elevation view representingexamples of deformable bushings according to the present disclosure.

FIG. 7 is a schematic front elevation view representing examples ofdeformable bushings according to the present disclosure.

FIG. 8 is a cross-sectional front side isometric view of a first exampleof a deformable bushing according to the present disclosure.

FIG. 9 is a cross-sectional front side isometric view of a secondexample of a deformable bushing according to the present disclosure.

DESCRIPTION

FIGS. 1-9 provide illustrative, non-exclusive examples of nacelle inletstructures 100, of engine assemblies 30 including nacelle inletstructures 100, of vehicles 10 including engine assemblies 30 and/ornacelle inlet structures 100, of deformable bushings 200, and/or ofmethods 300 of manufacturing an inlet inner barrel 140 of nacelle inletstructure 100, according to the present disclosure. Elements that servea similar, or at least substantially similar, purpose are labeled withlike numbers in each of FIGS. 1-9, and these elements may not bediscussed in detail herein with reference to each of FIGS. 1-9.Similarly, all elements may not be labeled in each of FIGS. 1-9, butreference numerals associated therewith may be utilized herein forconsistency. Elements, components, and/or features that are discussedherein with reference to one or more of FIGS. 1-9 may be included inand/or utilized with any of FIGS. 1-9 without departing from the scopeof the present disclosure. Generally, in the Figures, elements that arelikely to be included in a given example are illustrated in solid lines,while elements that are optional to a given example are illustrated indashed lines. However, elements that are illustrated in solid lines arenot essential to all examples of the present disclosure, and an elementshown in solid lines may be omitted from a given example withoutdeparting from the scope of the present disclosure. Additionally, insome Figures, one or more components and/or portions thereof that areobscured from view also may be illustrated in dashed lines.

FIG. 1 illustrates an example of a vehicle 10 that includes engineassemblies 30 with nacelle inlet structures 100 according to the presentdisclosure. In particular, in the example of FIG. 1, vehicle 10 is anaircraft 20 that includes a fuselage 22, a pair of wings 24 extendingfrom fuselage 22, and a tail 26. In the example of FIG. 1, each wing 24supports a respective engine assembly 30 that includes nacelle inletstructure 100.

FIGS. 2-4 schematically illustrate examples and aspects of engineassemblies 30 including nacelle inlet structures 100. In particular,FIG. 2 is a schematic cross-sectional illustration of engine assembly 30including nacelle inlet structure 100, while FIG. 3 is a schematiccross-sectional illustration of a portion of an example of nacelle inletstructure 100 in isolation. In the example of FIG. 2, engine assembly 30additionally includes an engine case 40 that is operatively coupled tonacelle inlet structure 100. In some examples, and as schematicallyillustrated in FIG. 2, engine assembly 30 includes a fan 60, and enginecase 40 includes, or is, a fan case 42 that at least substantiallyencloses fan 60. In particular, FIG. 2 schematically illustrates anexample in which engine assembly 30 is a turbofan engine that includes agas turbine engine 70 for driving fan 60, which in turn operates togenerate thrust to propel vehicle 10. However, this is not required ofall examples of engine assembly 30, and it is additionally within thescope of the present disclosure that engine assembly 30 may includeand/or be any of a variety of engine types, examples of which include ajet engine and a turbojet engine.

In some examples, and as schematically illustrated in FIG. 2, fan 60includes a plurality of fan blades 62 that are configured to rotateabout an engine axis 32 of engine assembly 30 under the power of gasturbine engine 70 to generate a thrust to propel vehicle 10. In the caseof an extreme event that stresses engine assembly 30 beyond standardengineering thresholds, such as due to an intake of foreign debris intoengine assembly 30, engine assembly 30 may experience a fan blade off(FBO) event in which at least one fan blade 62 departs from fan 60during operative use of engine assembly 30, thus applying large radialand/or axial forces to components of engine assembly 30. Accordingly, itis desirable to engineer engine assembly 30 such that the remainingcomponents of engine assembly 30 remain intact and/or coupled to oneanother subsequent to an FBO event so as to avoid further damage tovehicle 10. Accordingly, nacelle inlet structures 100 and deformablebushings 200 according to the present disclosure are configured towithstand the axial and/or radial loads associated with an FBO eventsuch that nacelle inlet structure 100 remains coupled to engine case 40in such an event.

As used herein, the term “axial,” as used to describe a direction and/ora directionality of a force, is intended to refer to a direction that isaligned with, parallel to, and/or at least substantially parallel toengine axis 32. As used herein, the term “radial,” as used to describe adirection and/or a directionality of a force, is intended to refer to adirection that is perpendicular to, or at least substantiallyperpendicular to, engine axis 32, such as a direction that is directedtoward or away from engine axis 32.

As schematically illustrated in FIGS. 2-3, nacelle inlet structure 100includes an inlet outer barrel 130 and an inlet inner barrel 140, eachof which extends circumferentially around engine axis 32 of engineassembly 30 (shown in FIG. 2) and extends at least partially along adirection parallel to engine axis 32. In particular, and asschematically illustrated in FIG. 2, inlet outer barrel 130 at leastsubstantially encloses inlet inner barrel 140. In this manner, inletinner barrel 140 defines a duct for directing air into engine assembly30, while inlet outer barrel 130 defines at least a portion of anexterior surface of engine assembly 30.

As used herein, the term “at least partially,” as used to describe anextent of a component relative to a stated axis or direction, isintended to refer to a configuration in which at least two points alongthe extent of the component are spaced apart along the stated axis ordirection. In some more specific examples, the two points of thecomponent refer to points that are maximally spaced apart along a majordimension of the component. Accordingly, as an example, inlet innerbarrel 140 may be described as extending at least partially along adirection parallel to engine axis 32 because various points on inletinner barrel 140 are spaced apart along a direction parallel to engineaxis 32. However, such descriptions do not require that the statedcomponent itself extend parallel to, or at least substantially parallelto, the stated axis or direction, or along a single direction.

As schematically illustrated in FIGS. 2-4, inlet inner barrel 140includes a tubular portion 142 that extends at least partially along adirection parallel to engine axis 32 (shown in FIG. 2) and an inletattachment flange 144 extending from tubular portion 142. Specifically,in some examples, and as schematically illustrated in FIGS. 2-4, inletattachment flange 144 extends radially away from engine axis 32 (shownin FIG. 2) and along a direction at least substantially perpendicular toengine axis 32. In this manner, in such examples, inlet attachmentflange 144 extends at least substantially perpendicular to at least aportion of tubular portion 142. As schematically illustrated in FIGS. 2and 4, inlet attachment flange 144 is configured to be operativelycoupled to engine case 40 of engine assembly 30 to operatively couplenacelle inlet structure 100 to engine case 40, as described in moredetail herein. In various examples, inlet attachment flange 144 extendsfully circumferentially around engine axis 32.

In contrast to prior art nacelle inlet structures, nacelle inletstructures 100 according to the present disclosure are configured suchthat inlet attachment flange 144 is integrally formed with at least aportion of tubular portion 142 of inlet inner barrel 140. In particular,some prior art nacelle inlet structures include a discrete attachmentring that defines an attachment flange for coupling the prior artnacelle inlet structure to engine case 40. In some such examples, theattachment ring of the prior art nacelle inlet structure extendscircumferentially around the inlet inner barrel and is operativelycoupled to the inlet inner barrel, such as via mechanical fasteners.Such mechanical fasteners may be expensive and/or may necessitatetime-intensive installation and/or maintenance procedures. Additionally,in some examples, the metallic construction of the attachment ringand/or of the associated mechanical fasteners adds an undesirable weightto the overall prior art nacelle inlet structure. By contrast, forminginlet attachment flange 144 of nacelle inlet structures 100 of thepresent disclosure to be integrally formed with at least a portion oftubular portion 142 eliminates the need for such mechanical fasteners,and also offers weight benefits over the metallic attachment rings ofthe prior art. Accordingly, in various examples according to the presentdisclosure, inlet attachment flange 144 is operatively coupled totubular portion 142 without the use of mechanical fasteners.

As used herein, the terms “integrally formed,” “monolithic,” “unitary,”and the like, as used to describe a structural relationship between twoor more components, are intended to refer to examples in which thecomponents refer to respective portions, regions, segments, etc. of anotherwise continuous and/or undifferentiated structure. In this sense,the terms “integrally formed,” “monolithic,” “unitary,” and the like maybe used to distinguish alternative examples in which the respectivecomponents are formed separately and subsequently brought together, suchas via fasteners, adhesion, and/or other mechanical coupling.Additionally or alternatively, the terms “integrally formed,”“monolithic,” “unitary,” and the like may be used to describe acomposite structure that is formed of a plurality of plies and/orelements of a composite material, but that is formed (e.g., moldedand/or cured) to structurally unite the plurality of plies and/orelements of the composite material to yield a single continuouscomponent.

Inlet outer barrel 130 and inlet inner barrel 140 may be operativelycoupled to one another, and/or maintained in a spaced-apartconfiguration relative to one another, in any of a variety of manners.In some examples, and as schematically illustrated in FIGS. 2-3, nacelleinlet structure 100 includes a lipskin 110 extending between inlet outerbarrel 130 and inlet inner barrel 140 at least at a forward end 102 ofnacelle inlet structure 100. Accordingly, in such examples, lipskin 110may be described as forming a leading surface of nacelle inlet structure100. In some examples, lipskin 110 at least partially defines, ordefines at least a portion of, inlet outer barrel 130. Stateddifferently, in such examples, and as schematically illustrated in FIGS.2-3, lipskin 110 extends from forward end 102 toward inlet outer barrel130 in such a manner that lipskin 110 joins, abuts, and/or transitionsinto inlet outer barrel 130. Additionally or alternatively, in someexamples, and as schematically illustrated in FIGS. 2-3, inlet outerbarrel 130 includes and/or is an outside mold line (OML) panel 132 thatis operatively coupled to lipskin 110 and/or that extends adjacent tolipskin 110.

Similarly, in some examples, lipskin 110 at least partially defines, ordefines at least a portion of, inlet inner barrel 140. Stateddifferently, in such examples, and as schematically illustrated in FIGS.2-3, lipskin 110 extends from forward end 102 toward inlet inner barrel140 in such a manner that lipskin 110 joins, abuts, and/or transitionsinto inlet inner barrel 140. Additionally or alternatively, in someexamples, and as schematically illustrated in FIGS. 2-3, lipskin 110 isoperatively coupled to, and/or extends adjacent to, tubular portion 142of inlet inner barrel 140.

In some examples, and as schematically illustrated in FIGS. 2-4, nacelleinlet structure 100 additionally includes a forward bulkhead 112 (shownin FIGS. 2-3) and/or an aft bulkhead 114 extending between andoperatively coupled to each of inlet inner barrel 140 and inlet outerbarrel 130. In particular, in an example in which nacelle inletstructure 100 includes each of forward bulkhead 112 and aft bulkhead114, forward bulkhead 112 is positioned proximate to forward end 102 ofnacelle inlet structure 100 relative to aft bulkhead 114. While FIGS.2-4 schematically illustrate forward bulkhead 112 (shown in FIGS. 2-3)and aft bulkhead 114 in cross-section, it is to be understood thatforward bulkhead 112 and aft bulkhead 114 each typically are annularstructures extending fully circumferentially around engine axis 32 tosupport inlet inner barrel 140 and inlet outer barrel 130 relative toone another.

In some examples, and as schematically illustrated in FIGS. 2-4, nacelleinlet structure 100 additionally includes an annular load absorber 120that is operatively coupled to each of aft bulkhead 114 and inlet innerbarrel 140. Accordingly, in such examples, aft bulkhead 114 may bedescribed as being operatively coupled to inlet inner barrel 140 viaannular load absorber 120. While FIGS. 2-4 schematically illustrateannular load absorber 120 in cross-section, it is to be understood thatannular load absorber 120 typically is an annular structure extendingfully circumferentially around engine axis 32 to support a fullcircumference of aft bulkhead 114.

Annular load absorber 120 may be operatively coupled to each of aftbulkhead 114 and inlet inner barrel 140 in any of a variety of manners.In particular, in some examples, and as schematically illustrated inFIGS. 3-4, nacelle inlet structure 100 additionally includes a pluralityof absorber fasteners 124 (one of which is visible in each of FIGS. 3-4)that operatively couple annular load absorber 120 to aft bulkhead 114.In such examples, each absorber fastener 124 may include and/or be anyof a variety of fasteners, examples of which include a mechanicalfastener, a bolt, a rivet, a blind fastener, etc. Additionally oralternatively, in some examples, and as schematically illustrated inFIGS. 2-4, annular load absorber 120 is operatively and/or directlycoupled to inlet attachment flange 144 of inlet inner barrel 140.

As discussed, nacelle inlet structure 100 generally is configured to beoperatively coupled to engine case 40 via inlet attachment flange 144.In particular, in some examples, and as schematically illustrated inFIGS. 2 and 4, inlet attachment flange 144 is configured to beoperatively coupled to fan case 42, such as via a fan case attachmentflange 44 of fan case 42, to operatively couple nacelle inlet structure100 to engine case 40. More specifically, in some such examples, and asschematically illustrated in FIGS. 2 and 4, inlet attachment flange 144is configured to abut and/or directly engage fan case 42 when nacelleinlet structure 100 is operatively coupled to engine case 40.

In some examples, and as schematically illustrated in FIGS. 3-4, engineassembly 30 and/or nacelle inlet structure 100 includes a plurality offlange bolt assemblies 170 (one of which is visible in each of FIGS.3-4) for operatively coupling inlet attachment flange 144 to engine case40. In particular, in some such examples, and as best seen in FIG. 4,each flange bolt assembly 170 includes a respective flange bolt 172 witha respective flange bolt head 176 and a respective flange bolt shank 178extending away from the respective flange bolt head 176 along arespective flange bolt axis 174.

Each flange bolt assembly 170 may be configured to engage nacelle inletstructure 100 and engine case 40 in any of a variety of manners. In someexamples, and as schematically illustrated in FIG. 4, inlet attachmentflange 144 at least partially defines each of a plurality of inletflange bolt receivers 146 (one of which is visible in FIG. 4)circumferentially distributed around engine axis 32, and each inletflange bolt receiver 146 is configured to receive the respective flangebolt shank 178 of a respective flange bolt assembly 170. Morespecifically, in some such examples, and as schematically illustrated inFIG. 4, fan case attachment flange 44 defines a plurality of fan caseflange bolt receivers 46 (one of which is visible in FIG. 4) such thateach inlet flange bolt receiver 146 of inlet attachment flange 144 isaligned with a corresponding fan case flange bolt receiver 46 of fancase attachment flange 44. In such examples, the respective flange boltshank 178 of each flange bolt assembly 170 extends through each of arespective inlet flange bolt receiver 146 and the corresponding fan caseflange bolt receiver 46 to operatively couple nacelle inlet structure100 to engine case 40.

Each of the plurality of flange bolt assemblies 170 may include any of avariety of structures and/or components in addition to flange bolt 172,such as may be configured to slidingly and/or threadingly engage flangebolt 172. In particular, in some examples, and as schematicallyillustrated in FIGS. 3-4, each flange bolt assembly 170 additionallyincludes a respective nut 180 for threadingly engaging the respectiveflange bolt 172, such as to retain flange bolt 172 relative to inletflange bolt receiver 146 and fan case flange bolt receiver 46.

Additionally or alternatively, in some examples, and as schematicallyillustrated in FIGS. 3-4, each flange bolt assembly 170 additionallyincludes a respective deformable spacer 182 that is configured to bepositioned on the respective flange bolt shank 178 external to inletattachment flange 144. In particular, in some such examples, deformablespacer 182 is configured to be positioned between and engage flange bolthead 176 and either of fan case attachment flange 44 and inletattachment flange 144.

When present, deformable spacer 182 is configured to undergo a plasticdeformation upon receiving an applied compressive load (e.g., along adirection parallel to flange bolt axis 174) that is greater than athreshold compressive load. In particular, in some examples, eachdeformable spacer 182 is configured to deform plastically responsive toa shock or impact load that corresponds to a force that urges fan caseattachment flange 44 and inlet attachment flange 144 away from oneanother. More specifically, in the event that such a force is greaterthan the threshold compressive load, deformable spacer 182 absorbsenergy from the load via plastic deformation of deformable spacer 182,thus mitigating the risk of such a load causing damage to flange bolt172, fan case attachment flange 44, and/or inlet attachment flange 144.In some examples, the threshold compressive load at which deformablespacer 182 plastically deforms corresponds to, and/or is less than, aload that is associated with an FBO event. Examples and/or aspects ofdeformable spacers 182 that may be utilized in conjunction with nacelleinlet structure 100 are disclosed in U.S. Pat. No. 10,113,602, thecomplete disclosure of which is hereby incorporated by reference.

Additionally or alternatively, in some examples, and as schematicallyillustrated in FIG. 4, each flange bolt assembly 170 additionallyincludes a respective bushing 184 that is configured to be positionedwithin the respective inlet flange bolt receiver 146 to provide abearing between the respective flange bolt shank 178 and the respectiveinlet flange bolt receiver 146. Such a configuration may be especiallybeneficial in examples in which inlet attachment flange 144 is formed ofa composite material, such as a carbon fiber-reinforced material. Inparticular, in such examples, bushing 184 may operate to restrict and/orprevent blooming of the carbon fibers at and/or into inlet flange boltreceiver 146.

In some examples, and as schematically illustrated in FIGS. 4 and 6-7and less schematically in FIGS. 8-9, bushing 184 is a deformable bushing200 that is configured to undergo a plastic deformation upon receivingan applied load that is greater than a threshold bushing deformationload. As schematically illustrated in FIGS. 4 and 6, deformable bushings200 according to the present disclosure are configured to provide abearing between a flange bolt shank 278 of a flange bolt 272 and aflange bolt receiver 246 of an attachment flange 244. In particular,FIG. 4 schematically illustrates an example in which flange bolt 272 isflange bolt 172, flange bolt shank 278 is flange bolt shank 178,attachment flange 244 is inlet attachment flange 144, and flange boltreceiver 246 is inlet flange bolt receiver 146. However, this is notrequired of all examples of deformable bushing 200, and it isadditionally within the scope of the present disclosure that deformablebushing 200 may be utilized in conjunction with flange bolts 272 and/orattachment flanges 244 in any suitable context and/or application.Examples and/or features of deformable bushing 200 are described in moredetail below with reference to FIGS. 6-9.

In some examples, and as discussed, annular load absorber 120 isoperatively coupled to inlet inner barrel 140. In some such examples,the plurality of flange bolt assemblies 170 also operate to operativelycouple annular load absorber 120 to inlet inner barrel 140, such thatannular load absorber 120 is operatively coupled to inlet attachmentflange 144 via the plurality of flange bolt assemblies 170. Inparticular, in some such examples, and as schematically illustrated inFIG. 4, annular load absorber 120 defines a plurality of load absorberbolt receivers 122 (one of which is visible in FIG. 4), and each inletflange bolt receiver 146 is aligned with a corresponding load absorberbolt receiver 122. Accordingly, in such examples, and as schematicallyillustrated in FIG. 4, each flange bolt shank 178 extends through eachof a respective inlet flange bolt receiver 146 and the correspondingload absorber bolt receiver 122 when annular load absorber 120 isoperatively coupled to fan case attachment flange 44. However, this isnot required of all examples of nacelle inlet structure 100, and itadditionally is within the scope of the present disclosure that annularload absorber 120 may be operatively and/or directly coupled to anothercomponent of inlet inner barrel 140, such as tubular portion 142.

Inlet inner barrel 140 may exhibit and/or include any of a variety ofconfigurations, structures, and/or components. For example, and asdiscussed, inlet inner barrel 140 may be described as including tubularportion 142 and inlet attachment flange 144. In some examples, and asschematically illustrated in FIGS. 2-4, inlet inner barrel 140 and/ortubular portion 142 additionally includes a back skin 152 that facestoward inlet outer barrel 130 and/or a face sheet 154 that faces towardengine axis 32 (shown in FIG. 2) and that is at least partially spacedapart from back skin 152. In some examples, and as perhaps bestillustrated in FIG. 4, a portion of face sheet 154 extends radially awayfrom engine axis 32 (shown in FIG. 2) such that face sheet 154 extendsadjacent to at least a portion of inlet attachment flange 144. Inparticular, in some such examples, and as illustrated in FIG. 4, backskin 152 engages, intersects, and/or is integrally formed with facesheet 154.

When present, and as schematically illustrated in FIGS. 2-4, back skin152 is integrally formed with inlet attachment flange 144. Inparticular, in such examples, tubular portion 142 of inlet inner barrel140 includes at least a portion of back skin 152 such that inletattachment flange 144 is integrally formed with at least a portion oftubular portion 142; namely, at least the portion of tubular portion 142that forms back skin 152. More specifically, in some examples, and asdiscussed in more detail below in conjunction with FIG. 5, inletattachment flange 144 and back skin 152 are formed in a compositemanufacturing process as a unitary composite structure. In particular,in some examples, and as schematically illustrated in FIGS. 3-4, inletinner barrel 140 includes a composite laminate 106 that includes each ofinlet attachment flange 144 and back skin 152. Stated differently, insuch examples, inlet attachment flange 144 and back skin 152 may bedescribed as representing respective components and/or regions of acomposite laminate 106. In some such examples, and as schematicallyillustrated in FIGS. 3-4, inlet inner barrel 140 and/or tubular portion142 includes a barrel base structure 108 such that composite laminate106 is operatively coupled to barrel base structure 108.

In some examples, nacelle inlet structure 100 additionally oralternatively includes one or more structures for mitigating and/orattenuating an acoustic noise generated during operative use of engineassembly 30. In particular, in some examples, and as schematicallyillustrated in FIGS. 2-4, inlet inner barrel 140 includes an acousticstructure 150 for mitigating acoustic noise generated by engine assembly30. In some such examples, and as schematically illustrated in FIGS.2-4, tubular portion 142 of inlet inner barrel 140 includes acousticstructure 150. Additionally or alternatively, in some examples, and asschematically illustrated in FIGS. 3-4, barrel base structure 108includes at least a portion of acoustic structure 150.

In some examples, and as schematically illustrated in FIGS. 2-4,acoustic structure 150 includes an acoustic structure core 156 thatoperates to mitigate and/or attenuate the acoustic noise generated byengine assembly 30. In some such examples, at least a portion ofacoustic structure core 156 extends between back skin 152 and face sheet154. Additionally or alternatively, in some examples, acoustic structure150 includes at least a portion of back skin 152 and/or at least aportion of face sheet 154. When present, acoustic structure 150 and/oracoustic structure core 156 may include and/or be any of a variety ofstructures that are known to the art of acoustic engineering, examplesof which include an acoustic panel, an acoustic liner, a honeycombpanel, a resonator, and/or a Helmholtz resonator. As a more specificexample, acoustic structure core 156 may be a honeycomb core, and facesheet 154 may be a perforated face sheet 154 that enables acoustic wavesto traverse face sheet 154 into and out of acoustic structure core 156.

In some examples, and as schematically illustrated in FIGS. 3-4, inletinner barrel 140 may be described as including a flange transitionregion 148 extending between and interconnecting tubular portion 142 andinlet attachment flange 144. In particular, in such examples, flangetransition region 148 is integrally formed with each of inlet attachmentflange 144 and at least a portion of inlet inner barrel 140 and/or oftubular portion 142, such as back skin 152 and/or face sheet 154. Stateddifferently, in such examples, flange transition region 148 may bedescribed as referring to a portion (e.g., an annular portion) of inletinner barrel 140 within which tubular portion 142 and/or back skin 152transitions into inlet attachment flange 144. In some examples, and asschematically illustrated in FIGS. 3-4, flange transition region 148 issmoothly curved between tubular portion 142 and inlet attachment flange144.

In some examples, flange transition region 148 transitions, curves,and/or extends radially away from another component of inlet innerbarrel 140, such as tubular portion 142 and/or acoustic structure 150.In some such examples, and as schematically illustrated in FIGS. 3-4,inlet inner barrel 140 includes and/or defines an inlet radius channel104 that is defined between flange transition region 148 and one or moreother portions of inlet inner barrel 140, such as barrel base structure108, tubular portion 142, acoustic structure 150, back skin 152, and/orface sheet 154. In particular, in some examples, and as schematicallyillustrated in FIGS. 3-4, inlet radius channel 104 corresponds to aregion that is defined between composite laminate 106 and barrel basestructure 108 in a region adjacent to flange transition region 148.Additionally or alternatively, in some examples, and as schematicallyillustrated in FIGS. 3-4, flange transition region 148 corresponds to aportion of back skin 152 that curves radially away from acousticstructure 150, thus defining inlet radius channel 104 between flangetransition region 148 and acoustic structure 150. In some such examples,the portion of acoustic structure 150 adjacent to inlet radius channel104 may be described as being a portion of barrel base structure 108,while the portion of back skin 152 that curves away from acousticstructure 150 may be described as being a portion of composite laminate106. Additionally or alternatively, in some examples, and as perhapsbest illustrated in FIG. 4, inlet radius channel 104 is defined betweenflange transition region 148, a portion of back skin 152, and a portionof face sheet 154. In this manner, in such examples, inlet radiuschannel 104 may be described as being at least substantially boundedand/or enclosed by flange transition region 148, back skin 152, and facesheet 154. In such examples, inlet radius channel 104 may be describedas being defined between flange transition region 148 and a portion oftubular portion 142 that includes back skin 152 and/or face sheet 154.

While the present disclosure generally relates to examples in whichcomposite laminate 106 includes a portion of back skin 152 that curvesaway from acoustic structure 150 and inlet attachment flange 144, itadditionally is within the scope of the present disclosure thatcomposite laminate 106 further encompasses any other composite materialsthat are molded and/or structurally united with back skin 152 and inletattachment flange 144. In particular, in some examples in which inletradius channel 104 is defined between flange transition region 158, aportion of back skin 152, and a portion of face sheet 154, compositelaminate 106 may be described as including at least a portion of backskin 152 and/or of face sheet 154, such as a portion that at leastpartially defines inlet radius channel 104.

In some examples in which inlet inner barrel 140 includes inlet radiuschannel 104, and as schematically illustrated in FIGS. 3-4, inlet innerbarrel 140 additionally includes an inlet radius filler 160 that isreceived within inlet radius channel 104. In particular, in some suchexamples, and as schematically illustrated in FIGS. 3-4, inlet radiusfiller 160 at least substantially fills inlet radius channel 104. Inparticular, in such examples, inlet radius filler 160 may be configuredto enhance a rigidity of inlet attachment flange 144 relative to tubularportion 142, such as by restricting inlet attachment flange 144 frombending, flexing, etc. relative to tubular portion 142. When present,inlet radius filler 160 may be formed of any of a variety of radiusfiller materials, examples of which include chopped carbon fibers, arigid material, an epoxy, a cured epoxy, and a potting compound. In someexamples, inlet radius filler 160 also may be referred to as a noodle160. In an example in which inlet radius channel 104 is at leastsubstantially bounded and/or enclosed by flange transition region 148,back skin 152, and face sheet 154, such as in the example of FIG. 4,such a configuration thus may ensure that inlet radius filler 160 alsois at least substantially bounded and/or enclosed by flange transitionregion 148, back skin 152, and face sheet 154, thereby facilitatingforming a robust bond between such elements during manufacture ofnacelle inlet structure 100.

FIG. 5 represents a flowchart depicting methods 300, according to thepresent disclosure, of manufacturing an inlet inner barrel of a nacelleinlet structure, such as inlet inner barrel 140 of nacelle inletstructure 100 as descried herein. As shown in FIG. 5, methods 300include forming, at 320, a composite laminate that includes a back skin(such as back skin 152 of inlet inner barrel 140) and an inletattachment flange (such as inlet attachment flange 144 of inlet innerbarrel 140). In particular, the forming the composite laminate at 320includes forming with a composite manufacturing process, as describedherein. Examples of composite laminates that may be formed via methods300 are described herein with reference to composite laminate 106. Inparticular, as used herein with reference to methods 300, the term“composite laminate” is intended to refer to a structure that is formedof a plurality of plies of a composite material and that includesregions corresponding to a back skin and an inlet attachment flange asdescribed herein. Accordingly, as used herein with reference to methods300, the term “composite laminate” may be used to refer to such astructure as embodied at any appropriate step of methods 300, and thusmay refer to a structure that is not yet fully formed and/or cured.

In some examples, and as shown in FIG. 5, the forming the compositelaminate at 320 includes molding, at 322, a plurality of plies of acomposite material to define each of the back skin and the inletattachment flange and, subsequent to the molding the plurality of pliesof the composite material at 322, curing, at 326, the plurality of pliesof the composite material to solidify the composite laminate. Thecomposite material may include and/or be any of a variety of materialsknown to the art of composite manufacturing, examples of which include afiber-reinforced material and/or a carbon fiber-reinforced material.

The molding the plurality of plies of the composite material at 322 mayinclude configuring the back skin and the inlet attachment flange in anyof a variety of manners. In some examples, the molding the plurality ofplies of the composite material at 322 includes configuring thecomposite laminate to include a number of plies of the compositematerial that varies across an extent of the composite laminate. Inparticular, in some examples, the molding the plurality of plies of thecomposite material at 322 includes forming the inlet attachment flangewith a greater number of plies of the composite material than the numberof plies of the composite material that form a tubular portion of theback skin. As more specific examples, in various examples, the inletattachment flange is formed to include about 20-50 plies of compositematerial, while one or more of a portion of the back skin, and/or of aface sheet (such as face sheet 154 disclosed herein) spaced apart fromthe inlet attachment flange are formed to include about 1-6 plies ofcomposite material. In this manner, the molding the plurality of pliesof the composite material at 322 may include configuring the compositelaminate to feature enhanced strength and/or rigidity in regionscorresponding to various components of the inlet inner barrel. Examplesof the tubular portion of the back skin are described herein withreference to the portion of tubular portion 142 of inlet inner barrel140 that is formed by back skin 152.

In various examples, the molding the plurality of plies of the compositematerial at 322 includes utilizing any of a variety of compositemanufacturing techniques, such as by assembling the plies of thecomposite material in and/or on a preformed mold and/or by compressingthe plies of the composite of material with a vacuum bag system.Similarly, in various examples, the curing the plurality of plies of thecomposite material at 326 includes utilizing any of a variety ofcomposite manufacturing techniques, such as curing the plurality ofplies of the composite material with an autoclave.

In some examples, the molding the plurality of plies of the compositematerial at 322 includes forming a flange transition region and an inletradius channel. Examples of flange transitions regions and/or inletradius channels that may pertain to methods 300 are described hereinwith reference to flange transition region 148 and/or inlet radiuschannel 104, respectively. In particular, in some examples, the moldingthe plurality of plies of the composite material at 322 includes moldingsuch that the plurality of plies of the composite material are curved(e.g., follow a curved profile) within the flange transition region suchthat positioning the plurality of plies of the composite materialrelative to another structure (e.g., the barrel base structure and/oranother component of the tubular portion of the inlet inner barrel)yields the inlet radius channel at least partially defined by the flangetransition region. In particular, in some examples, the molding theplurality of plies of composite material at 322 includes positioning thecomposite laminate relative to a barrel base structure (such as barrelbase structure 108 described herein) such that the inlet radius channelis defined between the composite laminate and the barrel base structure,such as at a location adjacent to the flange transition region.

In some such examples, and as shown in FIG. 5, methods 300 additionallyinclude, prior to the curing the plurality of plies of the compositematerial at 326, positioning, at 324, an inlet radius filler relative tothe composite laminate. Examples of inlet radius fillers that may beutilized in conjunction with methods 300 are described herein withreference to inlet radius filler 160. In some examples, the positioningthe inlet radius filler at 324 includes positioning the inlet radiusfiller within an inlet radius channel associated with the compositelaminate, such as inlet radius channel 104 described herein. Inparticular, in some examples, the positioning the inlet radius filler at324 is performed at least partially subsequent to the molding theplurality of plies of the composite material at 322 such that at least aportion of the inlet radius channel has been at least initially formedprior to the positioning the inlet radius filler at 324. In some otherexamples, the positioning the inlet radius filler at 324 and the moldingthe plurality of plies of the composite material at 322 are performed atleast partially concurrently. More specifically, in some such examples,the positioning the inlet radius filler at 324 includes positioning suchthat the inlet radius filler forms a portion of a mold that serves toshape the plurality of plies of the composite material. In suchexamples, the positioning the inlet radius filler at 324 may bedescribed as operating to at least partially form and/or define theinlet radius channel and/or the flange transition region. Additionallyor alternatively, in some examples, the inlet radius filler operates toat least partially support the plurality of plies of the compositematerial during the curing the plurality of plies of the compositematerial at 326.

Additionally or alternatively, in some examples, the molding theplurality of plies of the composite material at 322 is performed atleast partially subsequent to the positioning the inlet radius filler at324. In particular, in some examples, the molding the plurality of pliesof the composite material at 322 includes, subsequent to the positioningthe inlet radius filler at 324, positioning at least a portion of theback skin and/or of the face sheet adjacent to the inlet radius filler.In this manner, in such examples, at least substantially enclosingand/or encapsulating the inlet radius filler within the plurality ofplies of the composite material prior to the curing the plurality ofplies of the composite material at 326 may enhance a geometricalstability and/or rigidity of the cured composite laminate.

In some examples, and as shown in FIG. 5, methods 300 additionallyinclude, prior to the positioning the inlet radius filler at 324,forming, at 310, the inlet radius filler. More specifically in some suchexamples, and as shown in FIG. 5, the forming the inlet radius filler at310 includes molding, at 312, a radius filler material into a shapecorresponding to a shape of the inlet radius channel and/or solidifying,at 314, the radius filler material to form the inlet radius filler as asolid structure. As discussed above in the context of inlet radiusfiller 160, the radius filler material may include and/or be any of avariety of materials, examples of which include chopped carbon fibers, arigid material, an epoxy, a cured epoxy, and a potting compound. Invarious examples, forming the inlet radius filler as a solid structureprior to the positioning the inlet radius filler at 324 serves tofacilitate the forming the composite laminate at 320. In particular, insome such examples, and as discussed above, the solidified inlet radiusfiller operates as a rigid support and/or mold for the compositelaminate during the curing the plies of the composite material at 326,thus enhancing robustness and/or consistency in forming the compositelaminate.

In some examples, the forming the inlet radius filler at 310 includesforming the inlet radius filler as a single continuous structure, suchas a continuous annular structure. In other examples, the forming theinlet radius filler at 310 includes forming the inlet radius filler as aplurality of discrete (i.e., separately formed) radius filler segments.In such examples, the positioning the inlet radius filler at 324includes positioning each of the plurality of discrete radius fillersegments to collectively form the inlet radius filler. Forming the inletradius filler as a plurality of discrete radius filler segments mayserve to increase a rate of manufacturing the inlet inner barrelrelative to an example in which the inlet radius filler is formed as asingle continuous structure.

Turning now to FIGS. 6-9, and as discussed, deformable bushing 200 maybe configured and/or engineered to undergo a plastic deformation uponreceiving an applied load that is greater than a threshold bushingdeformation load. Deformable bushing 200 may include any of a variety offeatures that correspond to and/or yield such functionality. FIG. 6 is aschematic cross-sectional side elevation view representing examples ofdeformable bushings 200, while FIG. 7 is a schematic front elevationview representing examples of deformable bushings 200. FIG. 8 is across-sectional illustration of a first example of deformable bushing200, while FIG. 9 is a cross-sectional illustration of a second exampleof deformable bushing 200. As schematically illustrated in FIGS. 4 and6-9, deformable bushing 200 includes a bushing body 210 and a bushingbore 220 extending through bushing body 210 along a bushing axis 202. Asfurther schematically illustrated in FIGS. 4 and 6-9, bushing body 210includes a bushing outer surface 214 that is configured to engage flangebolt receiver 246 (schematically illustrated in FIG. 6) and a bushinginner surface 212 that at least partially defines bushing bore 220.Deformable bushing 200 is configured such that bushing body 210 retainsits shape under an applied compressive load that is applied to bushingbody 210 along a direction perpendicular to bushing axis 202 and that isless than the threshold bushing deformation load. As used herein, a loadand/or force that is applied to bushing body 210 along a directionperpendicular to bushing axis 202 also may be described as a radialload.

Deformable bushing 200 may be configured such that the threshold bushingdeformation load assumes any of a variety of values. In particular, insome examples, deformable bushing 200 is configured to deformplastically responsive to a shock or impact load that corresponds to aradial force that urges flange bolt shank 278 and an inner surface offlange bolt receiver 246 toward one another. As a more specific example,in which flange bolt receiver 246 is inlet flange bolt receiver 146 andflange bolt 272 is flange bolt 172, in the event that such a radialforce is greater than the threshold bushing deformation load, deformablebushing 200 absorbs energy from the load via plastic deformation ofbushing body 210, thus mitigating the risk of such a load causing damageto flange bolt 172, fan case attachment flange 44, and/or inletattachment flange 144. In this manner, utilizing deformable bushing 200in conjunction with inlet attachment flange 144 of nacelle inletstructure 100 may serve to relax a requirement that inlet attachmentflange 144 be configured to withstand applied loads comparable to thethreshold bushing deformation load. In particular, utilizing deformablebushing 200 in conjunction with inlet attachment flange 144 may yield astructure that satisfies necessary safety margins while allowing forinlet attachment flange 144 to be relatively thin (e.g., formed of fewerplies of composite material) compared to an example of nacelle inletstructure 100 that lacks deformable bushing 200.

In some examples, deformable bushing 200 is configured to undergoplastic deformation only when the applied compressive load is at leastequal to the threshold bushing deformation load. Stated differently, insuch examples, deformable bushing 200 is configured to retain its shape,strength, rigidity, etc. when exposed to compressive loads that aresmaller in magnitude than the threshold bushing deformation load, and toplastically deform and/or crush when the applied compressive load isequal to or greater than the threshold bushing deformation load.

In some examples, deformable bushing 200 is configured such that thethreshold bushing deformation load may be characterized relative to oneor more load magnitudes associated with engine assembly 30. For example,engine assembly 30 may be characterized by a load limit that representsa magnitude of a maximum dynamic load that is expected to be encounteredduring nominal operative use of engine assembly 30. In some suchexamples, deformable bushing 200 may be configured such that thethreshold bushing deformation load is roughly 2-3 times the load limit.More specifically, in some examples, a ratio of the threshold bushingdeformation load to the limit load is at least 1.8:1, at least 2:1, atleast 2.2:1, at least 2.4:1, at least 2.6:1, at least 2.8:1, at least3.0:1, at most 3.2:1, at most 2.9:1, at most 2.7:1, at most 2.5:1, atmost 2.3:1, at most 2.1:1, and/or at most 1.9:1. In this manner, in suchexamples, deformable bushing 200 is configured such that deformablebushing 200 does not undergo plastic deformation under normaloperational load levels or at typical limit load levels, but doesundergo plastic deformation at load levels associated with an FBO event.

Additionally or alternatively, in some cases, it may be desirable toconfigure deformable bushing 200 such that the threshold bushingdeformation load is greater than an ultimate load level that isassociated with engine assembly 30. In particular, as used herein, theultimate load level associated with engine assembly 30 refers to amagnitude of a maximum dynamic and/or transient load that may beencountered by engine assembly 30 without compromising a structuralintegrity of engine assembly 30, and may be roughly 1.5 times the loadlimit associated with engine assembly 30. Additionally or alternatively,in some examples, the threshold bushing deformation load corresponds to,and/or is less than, a load that is associated with an FBO event. Inparticular, in some examples, a load that is associated with an FBOevent also may be described as being roughly 2-3 times the load limitassociated with engine assembly 30. Additionally or alternatively, invarious examples the threshold bushing deformation load is at least 10kilonewtons (kN), at least 15 kN, at least 20 kN, at least 30 kN, atleast 40 kN, at most 50 kN, at most 35 kN, at most 25 kN, at most 17 kN,and/or at most 12 kN.

Deformable bushing 200 and/or bushing body 210 may be formed of any of avariety of materials, examples of which include a polymer, ahigh-strength polymer, a thermoplastic, and/or a thermoset plastic. Invarious examples, deformable bushing 200 is configured such that bushingbody 210 remains rigid, and/or undergoes only elastic deformation, uponreceipt of a radially applied force that is less than the thresholdbushing deformation load. In some more specific examples, bushing body210 is formed of a material that has an ultimate compressive strengththat is at least 100 megapascals (MPa), at least 200 MPa, at least 300MPa, at least 400 MPa, at most 500 MPa, at most 350 MPa, at most 250MPa, and/or at most 150 MPa. Additionally or alternatively, in someexamples, bushing body 210 is formed of a material that has acompressive modulus of elasticity at 23 degrees Celsius that is at least1 gigapasacal (GPa), at least 5 GPa, at least 10 GPa, at least 15 GPa,at least 20 GPa, at most 25 GPa, at most 17 GPa, at most 12 GPa, at most7 GPa, and/or at most 2 GPa.

Deformable bushing 200 may have any of a variety of shapes, structuralconfigurations, and/or geometrical features, such as may yield and/orcorrespond to the threshold bushing deformation load. Stateddifferently, in some examples, the minimum deformation load isdetermined not only by a material construction of bushing body 210 butalso by one or more structural and/or geometrical characteristics ofbushing body 210. In some examples, and as schematically illustrated inFIGS. 6-7 and less schematically illustrated in FIGS. 8-9, bushing body210 and/or bushing bore 220 is at least substantially cylindrical.Additionally or alternatively, in some examples, and as schematicallyillustrated in FIGS. 4 and 6-7 and less schematically in FIGS. 8-9,bushing body 210 includes a first bushing end 204 and a second bushingend 208 such that bushing bore 220 extends between and terminates ateach of first bushing end 204 and second bushing end 208. Morespecifically, in some examples, first bushing end 204 and second bushingend 208 are at least substantially parallel to one another, and/or oneor both of first bushing end 204 and second bushing end 208 is at leastsubstantially planar. In particular, in the example of FIG. 4, each offirst bushing end 204 and second bushing end 208 is planar and forms abearing surface that engages another component of engine assembly 30;namely, annular load absorber 120 and fan case attachment flange 44.

In some examples, first bushing end 204 and/or second bushing end 208has a shape that is configured to facilitate plastic deformation ofbushing body 210 when the applied compressive load is greater than thethreshold bushing deformation load. As an example, in some examples, andas schematically illustrated in FIGS. 6-7 and less schematicallyillustrated in FIG. 8, first bushing end 204 and/or second bushing end208 defines a respective bushing recess 206 that extends into bushingbody 210 and at least partially circumferentially around bushing axis202. In some examples, and as schematically illustrated in dashed linesin FIG. 7 and less schematically illustrated in FIG. 8, bushing recess206 is an annular groove that extends fully circumferentially aroundbushing axis 202. In other examples, and as schematically illustrated indash-dot lines in FIG. 7, bushing recess 206 includes, and/or consistsof, a plurality of spaced-apart recesses that are circumferentiallydistributed around bushing axis 202. In this manner, deformable bushing200 may be configured and/or engineered to exhibit desired structuraland/or material properties, such as the magnitude of the thresholdbushing deformation load, independent of the corresponding properties ofthe bulk material that forms bushing body 210. In particular, in someexamples, such properties may be attained at least partially viaappropriate configuration of bushing recess 206, such as via appropriateselection of the dimensions, depth, radial position, circumferentialextent, etc. of bushing recess 206.

Additionally or alternatively, in some examples, and as schematicallyillustrated in FIGS. 6-7 and less schematically illustrated in FIG. 9,bushing body 210 defines one or more longitudinal tunnels 224 extendingthrough bushing body 210 between first bushing end 204 and secondbushing end 208 (shown in FIG. 6). Stated differently, in such examples,and as schematically illustrated in FIG. 6, each longitudinal tunnel 224extends between and interconnects first bushing end 204 and secondbushing end 208. Accordingly, in some such examples, and asschematically illustrated in FIGS. 6-7 and less schematicallyillustrated in FIG. 9, each longitudinal tunnel 224 extends at leastsubstantially parallel to bushing bore 220.

In some examples, longitudinal tunnel(s) 224 is/are configured tofacilitate the plastic deformation of bushing body 210 when the appliedcompressive load is greater than the threshold bushing deformation load,such as by decreasing the threshold bushing deformation load relative tothat of an otherwise identical deformable bushing 200 that lackslongitudinal tunnels 224. Stated differently, when present, longitudinaltunnel(s) 224 may be described as decreasing a strength of deformablebushing 200 to withstand a radial applied force, relative to anotherwise identical deformable bushing 200 that lacks longitudinaltunnel(s) 224. In this manner, deformable bushing 200 may be configuredand/or engineered to exhibit desired structural and/or materialproperties, such as the magnitude of the threshold bushing deformationload, independent of the corresponding properties of the bulk materialthat forms bushing body 210. In particular, in some examples, suchproperties may be attained at least partially via appropriateconfiguration of longitudinal tunnel(s) 224, such as via appropriateselection of the number, dimension, location, distribution, etc. oflongitudinal tunnel(s) 224.

In some examples, deformable bushing 200 may be described in terms ofvarious diameters associated with bushing body 210. In particular, insome examples, and as schematically illustrated in FIGS. 6-7, bushingouter surface 214 defines a bushing outer diameter 216 and bushing bore220 defines a bushing inner diameter 222. In such examples, each ofbushing outer diameter 216 and bushing inner diameter 222 is measuredalong a direction perpendicular to bushing axis 202. More specifically,in some examples, a ratio of bushing outer diameter 216 to bushing innerdiameter 222 is at least 1.2:1, at least 1.5:1, at least 2:1, at least3:1, at least 5:1, at most 10:1, at most 7:1, at most 4:1, at most2.5:1, at most 1.7:1, and/or at most 1.3:1. In particular, configuringbushing body 210 such that the ratio of bushing outer diameter 216 tobushing inner diameter 222 is relatively large (e.g., at least 1.2:1)may yield an enhanced capacity of deformable bushing 200 to absorbenergy, such as by yielding a correspondingly large threshold bushingdeformation load.

FIGS. 8-9 provide less schematic illustrations of respective examples ofdeformable bushings 200. In particular, FIG. 8 is a cross-sectional viewof an example of deformable bushing 200 in which each of first bushingend 204 and second bushing end 208 defines a respective bushing recess206, each of which extends fully circumferentially around bushing axis202. In the example of FIG. 8, each of first bushing end 204 and secondbushing end 208 may be described as being at least substantially planar.Similarly, FIG. 9 is a cross-sectional view of another example ofdeformable bushing 200. In particular, in the example of FIG. 9, bushingbody 210 defines a plurality of longitudinal tunnels 224 extendingthrough bushing body 210 between first bushing end 204 and secondbushing end 208.

Illustrative, non-exclusive examples of inventive subject matteraccording to the present disclosure are described in the followingenumerated paragraphs:

A1. A deformable bushing (200) for providing a bearing between a flangebolt shank (278) of a flange bolt (272) and a flange bolt receiver (246)of an attachment flange (244), the deformable bushing (200) comprising:

-   -   a bushing body (210); and    -   a bushing bore (220) extending through the bushing body (210)        along a bushing axis (202);

wherein the bushing body (210) includes:

-   -   a bushing outer surface (214) that is configured to engage the        flange bolt receiver (246); and    -   a bushing inner surface (212) that at least partially defines        the bushing bore (220);

wherein the deformable bushing (200) is configured such that the bushingbody (210) retains its shape under an applied compressive load that isapplied to the bushing body (210) along a direction perpendicular to thebushing axis (202) and that is less than a threshold bushing deformationload; wherein the deformable bushing (200) is configured such that thedeformable bushing (200) undergoes plastic deformation when the appliedcompressive load is greater than the threshold bushing deformation load;and wherein the threshold bushing deformation load is at least 10kilonewtons (kN) and at most 50 kN.

A2. The deformable bushing (200) of paragraph A1, wherein the thresholdbushing deformation load is one or more of at least 15 kN, at least 20kN, at least 30 kN, at least 40 kN, at most 35 kN, at most 25 kN, atmost 17 kN, and at most 12 kN.

A3. The deformable bushing (200) of any of paragraphs A1-A2, wherein thedeformable bushing (200) is configured to be utilized in an engineassembly (30) that is characterized by a limit load that represents amagnitude of a maximum dynamic load expected to be encountered duringnominal operative use of the engine assembly (30); and wherein a ratioof the threshold bushing deformation load to the limit load is one ormore of at least 1.8:1, at least 2:1, at least 2.2:1, at least 2.4:1, atleast 2.6:1, at least 2.8:1, at least 3.0:1, at most 3.2:1, at most2.9:1, at most 2.7:1, at most 2.5:1, at most 2.3:1, at most 2.1:1, andat most 1.9:1.

A4. The deformable bushing (200) of any of paragraphs A1-A3, wherein thedeformable bushing (200) is configured to undergo plastic deformationonly when the applied compressive load is at least equal to thethreshold bushing deformation load.

A5. The deformable bushing (200) of any of paragraphs A1-A4, wherein thebushing body (210) is formed of a material that has an ultimatecompressive strength that is one or more of at least 100 megapascals(MPa), at least 200 MPa, at least 300 MPa, at least 400 MPa, at most 500MPa, at most 350 MPa, at most 250 MPa, and at most 150 MPa.

A6. The deformable bushing (200) of any of paragraphs A1-A5, wherein thebushing body (210) is formed of a material that has a compressivemodulus of elasticity at 23 degrees Celsius that is one or more of atleast 1 gigapasacal (GPa), at least 5 GPa, at least 10 GPa, at least 150GPa, at least 20 GPa, at most 25 GPa, at most 17 GPa, at most 12 GPa, atmost 7 GPa, and at most 2 GPa.

A7. The deformable bushing (200) of any of paragraphs A1-A6, wherein thebushing body (210) is formed of one or more of a polymer, ahigh-strength polymer, a thermoplastic, and a thermoset plastic.

A8. The deformable bushing (200) of any of paragraphs A1-A7, wherein thebushing body (210) is at least substantially cylindrical.

A9. The deformable bushing (200) of any of paragraphs A1-A8, wherein thebushing bore (220) is at least substantially cylindrical.

A10. The deformable bushing (200) of any of paragraphs A1-A9, whereinthe bushing outer surface (214) defines a bushing outer diameter (216),as measured along a direction perpendicular to the bushing axis (202);wherein the bushing bore (220) defines a bushing inner diameter (222),as measured along a direction perpendicular to the bushing axis (202);and wherein a ratio of the bushing outer diameter (216) to the bushinginner diameter (222) is one or more of at least 1.2:1, at least 1.5:1,at least 2:1, at least 3:1, at least 5:1, at most 10:1, at most 7:1, atmost 4:1, at most 2.5:1, at most 1.7:1, and at most 1.3:1.

A11. The deformable bushing (200) of any of paragraphs A1-A10, whereinthe bushing body (210) includes a first bushing end (204) and a secondbushing end (208); wherein the bushing bore (220) extends between andterminates at each of the first bushing end (204) and the second bushingend (208); and wherein one or more of:

(i) the first bushing end (204) and the second bushing end (208) are atleast substantially parallel to one another;

(ii) one or both of the first bushing end (204) and the second bushingend (208) is at least substantially planar; and

(iii) one or both of the first bushing end (204) and the second bushingend (208) has a shape that is configured to facilitate plasticdeformation of the bushing body (210) when the applied compressive loadis greater than the threshold bushing deformation load.

A12. The deformable bushing (200) of paragraph A11, wherein one or bothof the first bushing end (204) and the second bushing end (208) definesan respective bushing recess (206) that extends into the bushing body(210) and that extends at least partially circumferentially around thebushing axis (202).

A13. The deformable bushing (200) of paragraph A12, wherein therespective bushing recess (206) is an annular groove that extends fullycircumferentially around the bushing axis (202).

A14. The deformable bushing (200) of any of paragraphs A12-A13, whereinthe respective bushing recess (206) includes a plurality of spaced-apartrecesses circumferentially distributed around the bushing axis (202).

A15. The deformable bushing (200) of any of paragraphs A1-A14, whereinthe bushing body (210) defines one or more longitudinal tunnels (224)extending through the bushing body (210) between a/the first bushing end(204) and a/the second bushing end (208); wherein the one or morelongitudinal tunnels (224) are configured to facilitate plasticdeformation of the bushing body (210) when the applied compressive loadis greater than the threshold bushing deformation load.

B1. A nacelle inlet structure (100) of an engine assembly (30), thenacelle inlet structure (100) comprising:

-   -   an inlet inner barrel (140) extending circumferentially around        an engine axis (32) of the engine assembly (30) and extending at        least partially along a direction parallel to the engine axis        (32); and    -   an inlet outer barrel (130) at least substantially enclosing the        inlet inner barrel (140) and extending circumferentially around        the engine axis (32) and at least partially along a direction        parallel to the engine axis (32);

wherein the inlet inner barrel (140) includes:

-   -   a tubular portion (142) that extends at least partially along a        direction parallel to the engine axis (32); and    -   an inlet attachment flange (144) extending from the tubular        portion (142) and configured to be operatively coupled to an        engine case (40) of the engine assembly (30) to operatively        couple the nacelle inlet structure (100) to the engine case        (40);

wherein the inlet attachment flange (144) is integrally formed with atleast a portion of the tubular portion (142).

B2. The nacelle inlet structure (100) of paragraph B1, wherein the inletattachment flange (144) extends radially away from the engine axis (32)along a direction at least substantially perpendicular to the engineaxis (32).

B3. The nacelle inlet structure (100) of any of paragraphs B1-B2,wherein the inlet attachment flange (144) extends fullycircumferentially around the engine axis (32).

B4. The nacelle inlet structure (100) of any of paragraphs B1-B3,further comprising a lipskin (110) extending between the inlet outerbarrel (130) and the inlet inner barrel (140) at least at a forward end(102) of the nacelle inlet structure (100).

B5. The nacelle inlet structure (100) of paragraph B4, wherein thelipskin (110) at least partially defines the inlet outer barrel (130).

B6. The nacelle inlet structure (100) of any of paragraphs B4-B5,wherein the inlet outer barrel (130) includes, and optionally is, anoutside mold line (OML) panel (132) that is operatively coupled to thelipskin (110).

B7. The nacelle inlet structure (100) of any of paragraphs B4-B6,wherein the lipskin (110) at least partially defines the inlet innerbarrel (140).

B8. The nacelle inlet structure (100) of any of paragraphs B1-B7,further comprising an aft bulkhead (114) extending between andoperatively coupled to each of the inlet inner barrel (140) and theinlet outer barrel (130).

B9. The nacelle inlet structure (100) of paragraph B8, furthercomprising an annular load absorber (120) that is operatively coupled toeach of the aft bulkhead (114) and the inlet inner barrel (140); whereinthe aft bulkhead (114) is operatively coupled to the inlet inner barrel(140) via the annular load absorber (120).

B10. The nacelle inlet structure (100) of paragraph B9, furthercomprising a plurality of absorber fasteners (124) that operativelycouples the annular load absorber (120) to the aft bulkhead (114).

B11. The nacelle inlet structure (100) of any of paragraphs B9-B10,wherein the annular load absorber (120) is operatively coupled to theinlet attachment flange (144).

B12. The nacelle inlet structure (100) of any of paragraphs B1-B11,further comprising a forward bulkhead (112) extending between andoperatively coupled to each of the inlet inner barrel (140) and theinlet outer barrel (130).

B13. The nacelle inlet structure (100) of any of paragraphs B1-B12,wherein the inlet inner barrel (140) defines a duct for directing airinto the engine assembly (30).

B14. The nacelle inlet structure (100) of any of paragraphs B1-B13,wherein the inlet inner barrel (140) includes a back skin (152) thatfaces toward the inlet outer barrel (130); and wherein the back skin(152) is integrally formed with the inlet attachment flange (144).

B15. The nacelle inlet structure (100) of paragraph B14, wherein theinlet inner barrel (140) includes a composite laminate (106) thatincludes each of the inlet attachment flange (144) and the back skin(152).

B16. The nacelle inlet structure (100) of paragraph B15, wherein thetubular portion (142) includes a barrel base structure (108); andwherein the composite laminate (106) is operatively coupled to thebarrel base structure (108).

B17. The nacelle inlet structure (100) of any of paragraphs B14-B16,wherein the tubular portion (142) includes at least a portion of theback skin (152).

B18. The nacelle inlet structure (100) of any of paragraphs B14-17,wherein the inlet attachment flange (144) and the back skin (152) areformed in a composite manufacturing process as a unitary compositestructure.

B19. The nacelle inlet structure (100) of any of paragraphs B14-B18,wherein one or both of the inlet inner barrel (140) and the tubularportion (142) includes a face sheet (154) that faces toward the engineaxis (32); wherein at least a portion of the face sheet (154) is spacedapart from the back skin (152); and optionally wherein a portion of theface sheet (154) extends adjacent to at least a portion of the inletattachment flange (144).

B20. The nacelle inlet structure (100) of any of paragraphs B1-B19,wherein the inlet inner barrel (140) includes an acoustic structure(150) for mitigating acoustic noise generated by the engine assembly(30); optionally wherein the tubular portion (142) includes the acousticstructure (150).

B21. The nacelle inlet structure (100) of paragraph B20, wherein theacoustic structure (150) includes an acoustic structure core (156) thatoperates to mitigate acoustic noise generated by the engine assembly(30); optionally wherein at least a portion of the acoustic structurecore (156) extends between a/the back skin (152) and a/the face sheet(154).

B22. The nacelle inlet structure (100) of any of paragraphs B20-B21,wherein the acoustic structure (150) includes one or both of:

(i) at least a portion of a/the back skin (152); and

(i) at least a portion of a/the face sheet (154).

B23. The nacelle inlet structure (100) of any of paragraphs B20-B22,wherein one or both of the acoustic structure (150) and a/the acousticstructure core (156) includes, and optionally is, one or more of anacoustic panel, an acoustic liner, a honeycomb panel, a resonator, and aHelmholtz resonator.

B24. The nacelle inlet structure (100) of any of paragraphs B20-B23,wherein a/the barrel base structure (108) includes at least a portion ofthe acoustic structure (150).

B25. The nacelle inlet structure (100) of any of paragraphs B1-B24,wherein the inlet inner barrel (140) includes a flange transition region(148) extending between and interconnecting the tubular portion (142)and the inlet attachment flange (144); wherein the flange transitionregion (148) is integrally formed with the inlet attachment flange (144)and at least a portion of the tubular portion (142), optionally one orboth of a/the back skin (152) and a/the face sheet (154); and optionallywherein the flange transition region (148) is smoothly curved betweenthe tubular portion (142) and the inlet attachment flange (144).

B26. The nacelle inlet structure (100) of paragraph B25, wherein theinlet inner barrel (140) includes an inlet radius channel (104) definedbetween the flange transition region (148) and one or more otherportions of the inlet inner barrel (140), optionally one or more of thetubular portion (142), an/the acoustic structure (150), the back skin(152), and the face sheet (154); and wherein the inlet inner barrel(140) further includes an inlet radius filler (160) received within theinlet radius channel (104).

B27. The nacelle inlet structure (100) of paragraph B26, wherein theinlet radius channel (104) is defined between a/the composite laminate(106) and a/the barrel base structure (108) in a region adjacent to theflange transition region (148).

B28. The nacelle inlet structure (100) of any of paragraphs B26-B27,wherein the inlet radius filler (160) at least substantially fills theinlet radius channel (104).

B29. The nacelle inlet structure (100) of any of paragraphs B26-B28,wherein the inlet radius filler (160) is configured to enhance arigidity of the inlet attachment flange (144) relative to the tubularportion (142).

B30. The nacelle inlet structure (100) of any of paragraphs B26-B29,wherein the inlet radius filler (160) is formed of a radius fillermaterial that includes, and optionally is, one or more of chopped carbonfibers, a rigid material, an epoxy, a cured epoxy, and a pottingcompound.

B31. The nacelle inlet structure (100) of any of paragraphs B1-B30,wherein the engine case (40) includes, and optionally is, a fan case(42) that at least substantially encloses a fan (60) of the engineassembly (30).

B32. The nacelle inlet structure (100) of paragraph B31, wherein theinlet attachment flange (144) is configured to be operatively coupled tothe fan case (42), optionally a fan case attachment flange (44) of thefan case (42), to operatively couple the nacelle inlet structure (100)to the engine case (40).

B33. The nacelle inlet structure (100) of any of paragraphs B31-B32,wherein the inlet attachment flange (144) is configured to abut and/ordirectly engage the fan case (42) when the nacelle inlet structure (100)is operatively coupled to the engine case (40).

B34. The nacelle inlet structure (100) of any of paragraphs B31-B33,wherein the fan (60) includes a plurality of fan blades (62); andwherein the nacelle inlet structure (100) is configured such that thenacelle inlet structure (100) remains coupled to the engine case (40) inthe event that a fan blade (62) detaches from the fan (60) during use ofthe engine assembly (30).

B35. The nacelle inlet structure (100) of any of paragraphs B1-B34,further comprising a plurality of flange bolt assemblies (170) foroperatively coupling the inlet attachment flange (144) to the enginecase (40).

B36. The nacelle inlet structure (100) of paragraph B35, wherein eachflange bolt assembly (170) of the plurality of flange bolt assemblies(170) includes a respective flange bolt (172) with a respective flangebolt head (176) and a respective flange bolt shank (178) extending awayfrom the respective flange bolt head (176) along a respective flangebolt axis (174).

B37. The nacelle inlet structure (100) of any of paragraphs B1-B36,wherein the inlet attachment flange (144) is configured to beoperatively coupled to the engine case (40) via a/the plurality offlange bolt assemblies (170).

B38. The nacelle inlet structure (100) of paragraph B37, wherein theinlet attachment flange (144) at least partially defines each of aplurality of inlet flange bolt receivers (146) circumferentiallydistributed around the engine axis (32); wherein each inlet flange boltreceiver (146) of the plurality of inlet flange bolt receivers (146) isconfigured to receive a/the respective flange bolt shank (178) of arespective flange bolt assembly (170) of the plurality of flange boltassemblies (170).

B39. The nacelle inlet structure (100) of paragraph B38, wherein a/thefan case attachment flange (44) defines a plurality of fan case flangebolt receivers (46); and wherein each inlet flange bolt receiver (146)of the plurality of inlet flange bolt receivers (146) is aligned with acorresponding fan case flange bolt receiver (46) of the plurality of fancase flange bolt receivers (46) such that each respective flange boltshank (178) extends through a respective inlet flange bolt receiver(146) and the corresponding fan case flange bolt receiver (46) tooperatively couple the nacelle inlet structure (100) to the engine case(40).

B40. The nacelle inlet structure (100) of paragraph B39, wherein an/theannular load absorber (120) defines a plurality of load absorber boltreceivers (122); and wherein each inlet flange bolt receiver (146) ofthe plurality of inlet flange bolt receivers (146) is aligned with acorresponding load absorber bolt receiver (122) of the plurality of loadabsorber bolt receivers (122) such that each respective flange boltshank (178) extends through a respective inlet flange bolt receiver(146) and the corresponding load absorber bolt receiver (122) when theannular load absorber (120) is operatively coupled to the fan caseattachment flange (44).

B41. The nacelle inlet structure (100) of any of paragraphs B37-B40,wherein each flange bolt assembly (170) of the plurality of flange boltassemblies (170) further includes one or more of:

(i) a respective nut (180) for threadingly engaging the respectiveflange bolt (172);

(ii) a respective deformable spacer (182) configured to be positioned onthe respective flange bolt shank (178) external to the inlet attachmentflange (144); wherein the deformable spacer (182) is configured toundergo a plastic deformation upon receiving an applied compressive loadthat is greater than a threshold compressive load; and

(iii) a respective bushing (184) configured to be positioned within therespective inlet flange bolt receiver (146) to provide a bearing betweenthe respective flange bolt shank (178) and the respective inlet flangebolt receiver (146).

B42. The nacelle inlet structure (100) of paragraph B41, wherein therespective bushing (184) is the deformable bushing (200) of any ofparagraphs A1-A15.

B43. The nacelle inlet structure (100) of any of paragraphs B37-B42,when dependent from paragraph B9, wherein the annular load absorber(120) is operatively coupled to the inlet attachment flange (144) viathe plurality of flange bolt assemblies (170).

B44. The nacelle inlet structure (100) of any of paragraphs B1-B43,wherein the inlet attachment flange (144) is operatively coupled to thetubular portion (142) without the use of mechanical fasteners.

C1. A method (300) of manufacturing the inlet inner barrel (140) of thenacelle inlet structure (100) of any of paragraphs B1-B44, the methodcomprising:

forming (320), with a composite manufacturing process, a compositelaminate (106) that includes a/the back skin (152) and the inletattachment flange (144).

C2. The method (300) of paragraph C1, wherein the forming (320) thecomposite laminate (106) includes:

molding (322) a plurality of plies of a composite material to define theback skin (152) and the inlet attachment flange (144); and

subsequent to the molding (322) the plurality of plies of the compositematerial, curing (326) the plurality of plies of the composite materialto solidify the composite laminate (106).

C3. The method (300) of paragraph C2, wherein the composite materialincludes, and optionally is, a fiber-reinforced material, optionally acarbon fiber-reinforced material.

C4. The method (300) of any of paragraphs C2-C3, wherein the molding(322) the plurality of plies of the composite material includesconfiguring the composite laminate (106) to include a number of plies ofthe composite material that varies across an extent of the compositelaminate (106).

C5. The method (300) of paragraph C4, wherein the molding (322) theplurality of plies of the composite material includes forming the inletattachment flange (144) with a greater number of plies of the compositematerial than the number of plies of the composite material that forma/the tubular portion (142).

C6. The method (300) of any of paragraphs C2-C5, wherein the molding(322) the plurality of plies of the composite material includes forminga/the flange transition region (148) and an/the inlet radius channel(104).

C7. The method (300) of any of paragraphs C2-C6, wherein the molding(322) the plurality of plies of the composite material includespositioning the composite laminate (106) relative to a/the barrel basestructure (108) such that the inlet radius channel (104) is definedbetween the composite laminate (106) and the barrel base structure(108).

C8. The method (300) of any of paragraphs C2-C7, further comprising,prior to the curing (326) the plurality of plies of the compositematerial, positioning (324) an/the inlet radius filler (160) relative tothe composite laminate (106).

C9. The method (300) of paragraph C8, wherein the positioning (324) theinlet radius filler (160) includes positioning the inlet radius filler(160) within an/the inlet radius channel (104).

C10. The method (300) of any of paragraphs C8-C9, wherein thepositioning (324) the inlet radius filler (160) is performed at leastpartially subsequent to the molding (322) the plurality of plies of thecomposite material.

C11. The method (300) of any of paragraphs C8-C9, wherein the molding(322) the plurality of plies of the composite material is performed atleast partially subsequent to the positioning (324) the inlet radiusfiller (160).

C12. The method (300) of paragraph C11, wherein the molding (322) theplurality of plies of the composite material includes, subsequent to thepositioning (324) the inlet radius filler (160), positioning at least aportion of one or both of a/the back skin (152) and a/the face sheet(154) adjacent to the inlet radius filler (160).

C13. The method (300) of any of paragraphs C8-C12, wherein thepositioning (324) the inlet radius filler (160) and the molding (322)the plurality of plies of the composite material are performed at leastpartially concurrently.

C14. The method (300) of any of paragraphs C8-C13, further comprising,prior to the positioning (324) the inlet radius filler (160), forming(310) the inlet radius filler (160).

C15. The method (300) of paragraph C14, wherein the forming (310) theinlet radius filler (160) includes:

molding (312) a/the radius filler material into a shape corresponding toa shape of the inlet radius channel (104); and

solidifying (314) the radius filler material to form the inlet radiusfiller (160) as a solid structure.

C16. The method (300) of any of paragraphs C14-C15, wherein the forming(310) the inlet radius filler (160) includes forming the inlet radiusfiller (160) as a single continuous structure, optionally an annularstructure.

C17. The method (300) of any of paragraphs C14-C15, wherein the forming(310) the inlet radius filler (160) includes forming the inlet radiusfiller (160) as a plurality of discrete radius filler segments; andwherein the positioning (324) the inlet radius filler (160) includespositioning each of the plurality of discrete radius filler segmentsrelative to the composite laminate (106) to collectively form the inletradius filler (160).

D1. An engine assembly (30) comprising the nacelle inlet structure (100)of any of paragraphs B1-B44.

D2. The engine assembly (30) of paragraph D1, wherein the engineassembly (30) includes, and optionally is, one or more of a jet engine,a turbofan engine, and a turbojet engine.

D3. The engine assembly (30) of any of paragraphs D1-D2, wherein theengine assembly (30) includes a/the fan (60) and a gas turbine engine(70) for driving the fan (60).

D4. The engine assembly (30) of any of paragraphs D1-D3, furthercomprising:

a/the fan (60); and

a/the fan case (42) operatively coupled to the inlet attachment flange(144) and at least substantially enclosing the fan (60).

E1. A vehicle (10) comprising the engine assembly (30) of any ofparagraphs D1-D4.

E2. The vehicle (10) of paragraph E1, wherein the vehicle (10) is anaircraft (20) that includes a fuselage (22), one or more wings (24)extending from the fuselage (22), and a tail (26); and optionallywherein the one or more wings (24) support the engine assembly (30).

As used herein, the phrase “at least substantially,” when modifying adegree or relationship, includes not only the recited “substantial”degree or relationship, but also the full extent of the recited degreeor relationship. A substantial amount of a recited degree orrelationship may include at least 75% of the recited degree orrelationship. For example, a first direction that is at leastsubstantially parallel to a second direction includes a first directionthat is within an angular deviation of 22.5° relative to the seconddirection and also includes a first direction that is identical to thesecond direction.

As used herein, the terms “selective” and “selectively,” when modifyingan action, movement, configuration, or other activity of one or morecomponents or characteristics of an apparatus, mean that the specificaction, movement, configuration, or other activity is a direct orindirect result of one or more dynamic processes, as described herein.The terms “selective” and “selectively” thus may characterize anactivity that is a direct or indirect result of user manipulation of anaspect of, or one or more components of, the apparatus, or maycharacterize a process that occurs automatically, such as via themechanisms disclosed herein.

As used herein, the terms “adapted” and “configured” mean that theelement, component, or other subject matter is designed and/or intendedto perform a given function. Thus, the use of the terms “adapted” and“configured” should not be construed to mean that a given element,component, or other subject matter is simply “capable of” performing agiven function but that the element, component, and/or other subjectmatter is specifically selected, created, implemented, utilized,programmed, and/or designed for the purpose of performing the function.It is also within the scope of the present disclosure that elements,components, and/or other recited subject matter that is recited as beingadapted to perform a particular function may additionally oralternatively be described as being configured to perform that function,and vice versa. Similarly, subject matter that is recited as beingconfigured to perform a particular function may additionally oralternatively be described as being operative to perform that function.

As used herein, the term “and/or” placed between a first entity and asecond entity means one of (1) the first entity, (2) the second entity,and (3) the first entity and the second entity. Multiple entries listedwith “and/or” should be construed in the same manner, i.e., “one ormore” of the entities so conjoined. Other entities optionally may bepresent other than the entities specifically identified by the “and/or”clause, whether related or unrelated to those entities specificallyidentified. Thus, as a non-limiting example, a reference to “A and/orB,” when used in conjunction with open-ended language such as“comprising,” may refer, in one example, to A only (optionally includingentities other than B); in another example, to B only (optionallyincluding entities other than A); in yet another example, to both A andB (optionally including other entities). These entities may refer toelements, actions, structures, steps, operations, values, and the like.

As used herein, the phrase “at least one,” in reference to a list of oneor more entities should be understood to mean at least one entityselected from any one or more of the entities in the list of entities,but not necessarily including at least one of each and every entityspecifically listed within the list of entities and not excluding anycombinations of entities in the list of entities. This definition alsoallows that entities may optionally be present other than the entitiesspecifically identified within the list of entities to which the phrase“at least one” refers, whether related or unrelated to those entitiesspecifically identified. Thus, as a non-limiting example, “at least oneof A and B” (or, equivalently, “at least one of A or B,” or,equivalently “at least one of A and/or B”) may refer, in one embodiment,to at least one, optionally including more than one, A, with no Bpresent (and optionally including entities other than B); in anotherembodiment, to at least one, optionally including more than one, B, withno A present (and optionally including entities other than A); in yetanother embodiment, to at least one, optionally including more than one,A, and at least one, optionally including more than one, B (andoptionally including other entities). In other words, the phrases “atleast one,” “one or more,” and “and/or” are open-ended expressions thatare both conjunctive and disjunctive in operation. For example, each ofthe expressions “at least one of A, B, and C,” “at least one of A, B, orC,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A,B, and/or C” may mean A alone, B alone, C alone, A and B together, A andC together, B and C together, A, B, and C together, and optionally anyof the above in combination with at least one other entity.

As used herein, the phrase, “for example,” the phrase, “as an example,”and/or simply the term “example,” when used with reference to one ormore components, features, details, structures, embodiments, and/ormethods according to the present disclosure, are intended to convey thatthe described component, feature, detail, structure, embodiment, and/ormethod is an illustrative, non-exclusive example of components,features, details, structures, embodiments, and/or methods according tothe present disclosure. Thus, the described component, feature, detail,structure, embodiment, and/or method is not intended to be limiting,required, or exclusive/exhaustive; and other components, features,details, structures, embodiments, and/or methods, including structurallyand/or functionally similar and/or equivalent components, features,details, structures, embodiments, and/or methods, are also within thescope of the present disclosure.

In the present disclosure, several of the illustrative, non-exclusiveexamples have been discussed and/or presented in the context of flowdiagrams, or flow charts, in which the methods are shown and describedas a series of blocks, or steps. Unless specifically set forth in theaccompanying description, it is within the scope of the presentdisclosure that the order of the blocks may vary from the illustratedorder in the flow diagram, including with two or more of the blocks (orsteps) occurring in a different order, concurrently, and/or repeatedly.It is also within the scope of the present disclosure that the blocks,or steps, may be implemented as logic, which also may be described asimplementing the blocks, or steps, as logics. In some applications, theblocks, or steps, may represent expressions and/or actions to beperformed by functionally equivalent circuits or other logic devices.The illustrated blocks may, but are not required to, representexecutable instructions that cause a computer, processor, and/or otherlogic device to respond, to perform an action, to change states, togenerate an output or display, and/or to make decisions.

The various disclosed elements of apparatuses and systems and steps ofmethods disclosed herein are not required to all apparatuses, systems,and methods according to the present disclosure, and the presentdisclosure includes all novel and non-obvious combinations andsubcombinations of the various elements and steps disclosed herein.Moreover, one or more of the various elements and steps disclosed hereinmay define independent inventive subject matter that is separate andapart from the whole of a disclosed apparatus, system, or method.Accordingly, such inventive subject matter is not required to beassociated with the specific apparatuses, systems, and methods that areexpressly disclosed herein and such inventive subject matter may findutility in apparatuses, systems, and/or methods that are not expresslydisclosed herein.

It is believed that the disclosure set forth above encompasses multipledistinct inventions with independent utility. While each of theseinventions has been disclosed in its preferred form, the specificembodiments thereof as disclosed and illustrated herein are not to beconsidered in a limiting sense as numerous variations are possible. Thesubject matter of the inventions includes all novel and non-obviouscombinations and subcombinations of the various elements, features,functions and/or properties disclosed herein. Similarly, where theclaims recite “a” or “a first” element or the equivalent thereof, suchclaims should be understood to include incorporation of one or more suchelements, neither requiring nor excluding two or more such elements.

It is believed that the following claims particularly point out certaincombinations and subcombinations that are directed to one of thedisclosed inventions and are novel and non-obvious. Inventions embodiedin other combinations and subcombinations of features, functions,elements, and/or properties may be claimed through amendment of thepresent claims or presentation of new claims in this or a relatedapplication. Such amended or new claims, whether they are directed to adifferent invention or directed to the same invention, whetherdifferent, broader, narrower, or equal in scope to the original claims,are also regarded as included within the subject matter of theinventions of the present disclosure.

1. A nacelle inlet structure of an engine assembly, the nacelle inletstructure comprising: an inlet inner barrel extending circumferentiallyaround an engine axis of the engine assembly and extending at leastpartially along a direction parallel to the engine axis; and an inletouter barrel at least substantially enclosing the inlet inner barrel andextending circumferentially around the engine axis and at leastpartially along a direction parallel to the engine axis; wherein theinlet inner barrel includes: a tubular portion that extends at leastpartially along a direction parallel to the engine axis; and an inletattachment flange extending from the tubular portion and configured tobe operatively coupled to an engine case of the engine assembly tooperatively couple the nacelle inlet structure to the engine case;wherein the inlet attachment flange is integrally formed with at least aportion of the tubular portion.
 2. The nacelle inlet structure of claim1, wherein the inlet inner barrel includes a back skin that faces towardthe inlet outer barrel; and wherein the back skin is integrally formedwith the inlet attachment flange.
 3. The nacelle inlet structure ofclaim 2, wherein the inlet attachment flange and the back skin areformed in a composite manufacturing process as a unitary compositestructure.
 4. The nacelle inlet structure of claim 2, wherein the inletinner barrel includes: a face sheet that faces toward the engine axis;and an acoustic structure for mitigating acoustic noise generated by theengine assembly; wherein the tubular portion includes the acousticstructure; wherein at least a portion of the face sheet is spaced apartfrom the back skin; and wherein at least a portion of the acousticstructure extends between the back skin and the face sheet.
 5. Thenacelle inlet structure of claim 1, further comprising: an aft bulkheadextending between and operatively coupled to each of the inlet innerbarrel and the inlet outer barrel; and an annular load absorber that isoperatively coupled to each of the aft bulkhead and the inlet innerbarrel; wherein the aft bulkhead is operatively coupled to the inletinner barrel via the annular load absorber.
 6. The nacelle inletstructure of claim 1, wherein the inlet inner barrel includes a flangetransition region extending between and interconnecting the tubularportion and the inlet attachment flange; wherein the flange transitionregion is integrally formed with the inlet attachment flange and atleast a portion of the tubular portion; and wherein the flangetransition region is smoothly curved between the tubular portion and theinlet attachment flange.
 7. The nacelle inlet structure of claim 6,wherein the inlet inner barrel includes an inlet radius channel definedbetween the flange transition region and the tubular portion; andwherein the inlet inner barrel further includes an inlet radius fillerreceived within the inlet radius channel.
 8. The nacelle inlet structureof claim 7, wherein the inlet radius filler at least substantially fillsthe inlet radius channel; and wherein the inlet radius filler isconfigured to enhance a rigidity of the inlet attachment flange relativeto the tubular portion.
 9. The nacelle inlet structure of claim 1,further comprising a plurality of flange bolt assemblies; wherein theinlet attachment flange is configured to be operatively coupled to theengine case via the plurality of flange bolt assemblies; wherein eachflange bolt assembly of the plurality of flange bolt assemblies includesa respective flange bolt with a respective flange bolt head and arespective flange bolt shank extending away from the respective flangebolt head along a respective flange bolt axis; wherein the inletattachment flange at least partially defines each of a plurality ofinlet flange bolt receivers circumferentially distributed around theengine axis; wherein each inlet flange bolt receiver of the plurality ofinlet flange bolt receivers is configured to receive the respectiveflange bolt shank of a respective flange bolt assembly of the pluralityof flange bolt assemblies.
 10. The nacelle inlet structure of claim 9,wherein the engine case includes a fan case that at least substantiallyencloses a fan of the engine assembly; wherein the inlet attachmentflange is configured to be operatively coupled to a fan case attachmentflange of the fan case to operatively couple the nacelle inlet structureto the engine case; wherein the fan case attachment flange defines aplurality of fan case flange bolt receivers; and wherein each inletflange bolt receiver of the plurality of inlet flange bolt receivers isaligned with a corresponding fan case flange bolt receiver of theplurality of fan case flange bolt receivers such that each respectiveflange bolt shank extends through a respective inlet flange boltreceiver and the corresponding fan case flange bolt receiver tooperatively couple the nacelle inlet structure to the engine case. 11.The nacelle inlet structure of claim 9, wherein each flange boltassembly of the plurality of flange bolt assemblies further includes arespective deformable spacer positioned on the respective flange boltshank external to the inlet attachment flange; wherein the respectivedeformable spacer is configured to plastically deform upon receiving anapplied compressive load that is greater than a threshold compressiveload.
 12. The nacelle inlet structure of claim 9, wherein each flangebolt assembly of the plurality of flange bolt assemblies includes arespective bushing positioned within a respective inlet flange boltreceiver of the plurality of inlet flange bolt receivers to provide abearing between the respective flange bolt shank and the respectiveinlet flange bolt receiver.
 13. The nacelle inlet structure of claim 1,wherein the inlet attachment flange is operatively coupled to thetubular portion without the use of mechanical fasteners.
 14. An engineassembly comprising the nacelle inlet structure of claim
 1. 15. A methodof manufacturing the inlet inner barrel of the nacelle inlet structureof claim 1, the method comprising: forming, with a compositemanufacturing process, a composite laminate that includes a back skinand the inlet attachment flange.
 16. The method of claim 15, wherein theforming the composite laminate includes: molding a plurality of plies ofa composite material to define the back skin and the inlet attachmentflange; and curing the plurality of plies of the composite material tosolidify the composite laminate.
 17. The method of claim 16, wherein themolding the plurality of plies of the composite material includesforming a flange transition region extending between and interconnectingthe tubular portion and the inlet attachment flange and an inlet radiuschannel defined between the flange transition region and the tubularportion; and wherein the method further comprises, prior to the curingthe plurality of plies of the composite material, positioning an inletradius filler relative to the composite laminate.
 18. The method ofclaim 17, further comprising, prior to the positioning the inlet radiusfiller, forming the inlet radius filler; wherein the forming the inletradius filler includes: molding a radius filler material into a shapecorresponding to a shape of the inlet radius channel; and solidifyingthe radius filler material to form the inlet radius filler as a solidstructure.
 19. The method of claim 18, wherein the forming the inletradius filler includes forming the inlet radius filler as a singlecontinuous annular structure.
 20. The method of claim 18, wherein theforming the inlet radius filler includes forming the inlet radius filleras a plurality of discrete radius filler segments; and wherein thepositioning the inlet radius filler includes positioning each of theplurality of discrete radius filler segments relative to the compositelaminate to collectively form the inlet radius filler.